Method of making artificial teeth



Nov. 28, '1939.

F. R. FELCHER 2.181,694

METHOD OF MAKING ARTIFICIAL TEETH.

2 Sheets-Sheet 1 Filed June 18, 1938 Nov. 28, 1939.

F. R. FELCHER 2.18,694

METHOD OF MAKING ART'IFICIAL TEETH Filed June 18, 1938 2 Sheets-Sheet 2 Patented Nov. 28, 1939 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to improvements in means and methods for making artiiicial teeth and particularly for duplicating natural teeth.

The object of the invention is to provide novel methods and means whereby artificial teeth can readily be produced of accurately desired forms and shapes; which method shall be quite simple to practice and yetv produce accurate results and which shall be free of the detrimental features of 'the methods in common use at the present time.

One important feature of the invention relates to the ease by which holding or securing pins can be placed in the teeth in whatever position that will best result in the greatest strength when the tooth is secured to bridge Work or artificial dentures.

A further important feature relates to the ease by which a desired human tooth can be accurately duplicated.

A practical feature of the invention relates to a split metal mold box in which a soft rubber mold can be made in combination with a cover. plate for the box which extends over and fits upon both parts of the mold box and is adaptedV to carry the tooth or teeth to be duplicated.

The invention will be more readily understood by reference to the following specication and to the accompanying drawings forming part thereof and to the appended claims in which the invention is set forth in specific detail.

In said drawings:

Fig. 1 is a perspective View of an improved metal mold box which is especially ldesigned for practicing my improved method of making artificial teeth;

Fig. 2 is a top plan view of thefmetal mold bo partly in horizontal section on the line 2-2 of Fig. 1; v

Fig. 3 is a longitudinal central section of the mold box shown in Fig. 1;

Fig. 4 is a vertical, transverse section of the mold box illustrating the first step in the method;

Fig. 5 is a section similar to Fig. 4 and illustrating the second step in the method;

Fig. 6 is a section similar to Fig. 4 except that it is reversed and illustrating the third step in the method;

Fig. 7 is a section similar to Fig. 6 and illustrating the fourth step in the method;

Fig. 8 is a similar section and illustrating th fifth step of the method;

Fig. 9 is a fragmentary section illustrating one form of retaining members;

Figs. 10 and 11 are fragmentary sections illustrating another form of retaining member;

Figs. 12 and 13 are similar fragmentary sections for better illustrating the retaining member shown inFig. 9; and

Fig. 14 is a perspective View of a nished tooth.

My improved method of making artificial teeth consists of several simple steps and includes the use of a metal mold box and a cover and in which box a soft rubber mold can be made having a cavity in which to form a tooth, the cavity having been formed by the sample tooth or the tooth which it is desired to duplicate.

The metal box mold as shown at I5 comprises a lower open topped box-like part I6 which is made up oftwo similar longitudinal parts I'I and I8 which can be doweled together by suitable dowels I9 so as to be held in accurate register when placed together. These parts I'I and I8 meet on the longitudinal, vertical, central plane of the box as shown at 20 and during operation can be tightly clamped together by any suitable means. The lower part of the metal mold box is closed atvits top by a cover plate 2I which accurately ts within the upper edge of the lower part and can be held tightly in place by any suitable means. Thetwo parts of the box proper and the cover member may be chambered as shownV for facilitating the passage oi water through same to cool or warm the mold in the process of making the teeth.

'Ihe end walls 22 of the box proper are provided with thin slits 23 at their meeting edges for a purpose which will be described.

The cover member 2| is provided on its inner surface with depressions or pockets 24 in which a slight amount of clay can be placed for holding in place the teeth 25 which it is desired to duplicate as shown in Fig. 4, in which figure an original tooth has been secured in place on the cover plate and the cover plate has been placed upon the box mold proper. When placing the teeth to be duplicated in place upon the cover, the cover is turned over with its inside on top and each tooth has its base pressed down upon one of the small patches of clay. Then the two base parts I'I and I8 are brought together and placed down upon the cover thus providing a closed mold space 26 in which the teeth to be duplicated are flxed to the bottom of said space and are upstanding in the mold space. At this point the three parts of the metal mold are tightly clamped together and melted rubber is poured into the mold through holes 21 provided in the bottom, one hole serving as a. vent to let the air out of the box. These holes 21 are located off the center line of the mold, one in each part I'I and I8 so the moldsA and filling them with suitable tooth material, allowing the tooth material to harden and again opening the mold and removing the unred teeth.

4. The method as dened in claim 3 and including the step of forcing tubes into the Walls of the tooth mold cavities for receiving and holding retaining members in proper relation to the cavities during the completion of the method.

5. The herein described method of making artifcial teeth or other dentures, producing a yieldable mold by forming the mold material around the article to be reproduced, removing the article from the mold, thus providing a mold cavinto the mold cavity, said retaining member havv ing an enlarged inner end.

FRED R. FELCI-IER. 

